Air filters are one of the most misunderstood components of an air conditioning system. Most homeowners think they are simply designed to trap dirt and dust, so it doesn’t recirculate in your home. While this is partially true, its real purpose is to protect your system’s evaporator coils from dirt, dust and debris. Dirty, clogged evaporator coils can lead to a catastrophic system failure that could cost a great deal to repair.
Many homeowners go to their nearest home supply store and pick up a filter that they think will fit and install it without ever thinking about whether they’ve chosen the correct filter for their system. Using the wrong filter can lead to the same problems as using no filter at all. Below we’ll show you how to avoid using the wrong air filter.
- Make sure you use the right size filter: Use a tape measure and note the length and width of your filter’s holding area. Most filters are about a half-inch smaller than your measurements, so don’t worry if the fit is not exact. If you’re not sure, consult with a reputable HVAC contractor.
- Pick the correct MERV rating for your system: Every air filter comes with a MERV rating (Minimum Efficiency Reporting Value). This describes how fine the mesh of the filter is. For most homes, this ranges from 4 to 12. You may be tempted to choose 12 to get maximum protection, but that may cause airflow difficulties and place undue strain on your system. When in doubt, choose a filter with a MERV rating between 4 and 6. Again, if you’re unsure, consult with an HVAC contractor.
Make sure to replace your air filters on a regular basis. A good rule of thumb is to replace them every 3 months — depending on indoor air quality. If you suffer from respiratory issues or seasonal allergies, you may want to look into a high-quality air filtration system such as the Trane CleanEffects Air Filter